Balanced steam-valve



UNITED STATES PATENT OEEICE.

SAMUEL E. JARVIS, OF LANSING, MICHIGAN.

BALANCED STEAM-VALVE.

SPECIFICATION forming part of Letters Iatent No. 267,791, dated November 121, 1882.

Application filed August 81. 1882. (No model.)

To alt whom it may concern.:

Be it known that I, SAMUEL E. .Tl-Lavis, of Lansing, in the county of Ingham and State of Michigan, have invented new and useful Improvements in Balanced Steam Valves; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form a part of this specification.

The nature of this invention relates to certain-new and useful improvements in the construction of balanced steam-valves for steamengines; and

The object of the invention is, rst, to provide the valve with additional induction-ports, so as to more rapidly allow the steam to enter the cylinder; and, secondly, to secure a perfect balance ot' the valve in all its different positions. i

Figurel shows the valve-chest opening the induction-ports. Fig. 2 shows it in a position when such ports are closed. Fig. 3 is acrosssection on the linea; w in Fig. l.

In the accompanying drawings, which form a part of this specification, A represents the cylinder, and B the steam-chest, and `C the slide-valve. rIhe cylinder is what-is known asa three-ported7 one, a b bcingthe inductionports, and c the exhaust-port, aud all arranged in the usual way. The steam side of the slidevalve forms an exact counterpart of its exhaust side, both being parallel, and provided with the induction-ports d d d2 d3, which-are arranged and connected together as shown;

c is a central passage, which connects the exhaust-portf of the valve with a recess, g, of the same area, on the opposite side ofthe valve.

h h are small brass tubes, open at both ends,

Y and arranged between the ports d and f and d3 and j', and form steam-passages from the lower to the upper side of the valve.

G is a face-plate, provided with recesscsj t' 7c, which correspond in position and superficialarea exactly and respectively with theinduction and eduotion openings a b c in the valve-seat K of the cylinder. This faceplate is also provided with the anges I I,

which form guides for the slide-valve in its travel, and prevent the face-plate from pressing upon the valve and binding it, said faceplate acting as a guide for the valve by embracing it upon three of its sides. The faceplate G is prevented from lateral displacement in any proper manner, without, however, interfering with its vertical play, which is allowed to avery slight extent, as there is a little open space, l, left between the top of this plate and the valve-chest cover. This is to allow the valve to rise from its seat and pass water from the cylinder back to the chest.

lt will be seen, in the operation of the valve, that as soon as an induction-port inthe cylinder is uncovered steam will pass into the same y directly from the valve-chest, as in the usual mannerpand also indirectly through three `induction-ports in the valve, as in Fig. l, through the ports d d2 cl3, which pass the steam through the remaining port d into the induction-port a,

of the cylinder. This arrangement, being otherwise desirable, admits also of a more limited travel of the valve. The second object of my invention is likewise gained through this arrangement of the valve induction-ports d d d2 d3, as these ports, in addition to the port e and relief-ports h, willat all times form an equilibrium in pressure on both sides of the valve. The necessity of the brass tubes It l1J is clearly indicated in Fig. 2, as in this position of the valve they form the only effective relief-ports for balancing the same. It is clear that the same construction may be applied to a socalled double valve.

What I claim as my invention, and desire to secure by Letters Patent, is-

The valve C, having induction-ports@ d d2 cl3, balancing-passages h, and exhaust-port c, combined with the seat having ports c b c, and with the plate G, having eorrespondin g spaces, j i lc, and ianges I, the said plate G embracing the valve upon three sides, and being arranged to form space Z, as set forth.

SAMUEL E. JARVIS. 

